A New Method for Prediction of Local Heat Flux on Membrane Waterwall with Rifled Tubes of Subcritical Boilers

A simplified procedure for prediction of local heat flux on the membrane waterwall rifled tubes of a sub-critical boiler is presented which requires the measurement of metal temperature at the tube crown using a chordal thermocouple. An inverse problem of heat conduction was solved using an iterative procedure to calculate the outside heat absorption rate from conduction and convection related heat transfer equations. The temperature distribution over the cross-section of the tube was found using ANSYS-FLUENT software for different range of values of outside heat flux, inside heat transfer coefficient and operating pressures. ‘Predicted’ temperatures obtained from the solution of direct heat conduction problem has been used to solve for the outside heat flux.